Rotary compressor, pump, and the like



2 Sheets-Sheet 1 March 5, 1929. H. s. BROOM ROTARY COMPRESSOR, PUMP, AND THE LIKE Filed Dec. 30, 1926' March 5, 1929, s BROOM 1,704,240

ROTARY COMPRESSOR, PUMP, AND THE LiKE Filed Dec. 50, 1926 2 Sheets-Sheet 2 Patented Mar. 5, 1929.

UNITED STATES 1,704,240 PATENT OFFICE.

nanny SKEET BROOM, or HIGH 'WYCOMBE, ENGLAND.

ROTARY COMPRESSOR, PUMP, AND THE LIKE.

Application filed December 30, 1926, Serial No. 158,050, and in Great Britain February 23, 1926.

This invention relates to rotary con1pressors, pumps, exhausters and the like and has for its object to provide such devices ofan extremely eiiicient character which are simple in construction and cheap to manufacture.

in general rotary compressors and the like constructed according to the invention com prise a drum or cylinder supported so as to be freely rotatable on its own axis, and surrounding a rotor whose axis is parallel to but not coincident with the axis of the cylinder and the surface of which at one point comes closely adjacent or substantially in contact with the inner surface of the cylinder, the rotor having a number of projecting, preferably radially, and sliding vanes whose outer edges come into contact with the interior surface of the rotatingcylinderp Means are provided for closing in the open ends of the rotatable cylinder and the vanes extend to these means, so that the crescent shaped space between the outer surface of the rotor and the inner surface of the cylinder is divided into a number of chambers bv the vanes. These chambers are gradually created, attain a maximum and then disappear in the course of one rotation. Means are provided for admitting fluid through the closed ends or one closed end of the rotating cylinder during the creation of the chambers and other means in one or both closed ends for permitting the delivery of the fluid from these chambers during their shrinkage and iinal disappearance. Suit-able bearings are provided at the ends for the shaft of the rotor which is furnished with driving means and other bearings for the rotatable cylinder or parts carried thereby at the ends or in other suitable position or positions. The cylinder may be caused to rotate by the frictional engagement of the outer edges of the blades or in some cases. it as well as the rotor. may be driven in the same direction at the same. or diifercnt speeds. End casings, frameworks or the like may be provided for supporting the bearings and the inlet and outlet devices, and these frameworks or devices may be connected by a. bed or base. In addition they may be connected at the top or in an intermediate position for example by a protector framework or casing which encloses or partly encloses the rotating cylinder.

li'leans may be provided for keeping the air or other fluid, which is delivered under pressure, or which enters the intake, in the case of exhausters and vacuum pumps, clear of the rotatable cylinder or drum or carrier therefor at the pressure or delivery end or intake end of the machine as the case may be or both, to avoid setting up end thrust in the rotatable cylinder or drum owing to unbalanced pressure at each end-of the machine, which would otherwise result. For this purpose the delivery port at.the pressure end of the machine or the intake, or

may comprise means for opposing a contrary or back pressure to balance the possible leakage, or may consist in so constructing the vanes and the surfaces against which the edges or ends thereof slide that the said surfaces move with the freely rotating drum or cylinder, preferably having combined therewith packing means of any desired nature between them and the driven rotor. In this latter case the inlet and outlet to the chambers between the vanes which come in the closed end or ends of the rotatable drum or cylinder are close to the centre of rotation. lVith this construction also the inlet or outlet or both are adapted to coincide with the inlet or outlet passages in the body of the rotor between the vanes and in this manner communication is established between the inletor outlet and the chambers between the vanes. The inlet and outlet are suitably disposed in one or both ends of the machine and in desired angular relationship with each other according to the disposition of the chambers between the vanes.

In some cases the devices for opposing back pressure to the possible leakage may be combined with the structural devices as generally described for the same purpose.

The bearings for the rotatable drum or cylinder or parts carried thereby may come at the ends or other suitable position or positions and with some forms of apparatus the drum may be mounted directly in the inner race of a large ball hearing or may be directly mounted on one or more roller Ell till

' The lowermost c or main casing.

that the invention ma in outer end Oil the shown, and w Fig. l fr gmentary of one oi? pump, co

ructed accordino to one are the invention i an end elevation ot the rotor, o and rotating drum or cylinder, shown prereiiited lay serrations, pitching or other suitahle'de a to is in th form sl movement endwise is hept in with the rotor lay n. -=ion spring a and comes within a sleeve protecting nwardly trom'the rotor hearing, sleeve projecting outwardly coming over the first mentioned sle as to he slidahle thereon. hut prevented l'roin rotation. The spring structure in some tornis may he dispensed with.

The dished end covers let may he supported any suitahle manner and attached to a suitable hed. As shown. they are termed with flanges which are holteo to the llanges oi a casing or framework 9.6 spaced 'lroin and surrounding or partly surrounding the revolving cylinder 2l.

lit the suction or 1 ans ol' c Fig. 3 is a similar view to Fig, l hut shewing another method of carrying the inven tion into etlect.

Fig. t is an enlarged view ot' the "paclring etween the rotating drum and the tired end plates, in the dorm oil the invention s iewn in Pp l 5 is a sectional elevation ot' another term ot puinp constructed according-to the item the port plate 6 is an end elevation partly in section of the form of the pump shown in.

l is a similar view to Fig. l ing a further method of carrying the invention into elilect.

8 is a lragmentary sectl vaticn of Fig. 'l.

9 is a detail view...

ltlieterring to Figs. 1 and F25 the particular form 0T compressor or lolower therein shewn 10 carrying a cylin and a number oil radially arranged at soul-angular The rotor shalt 10 projects d is supported nlet end the port plate 29; is termed with a port 52;? or with po :s ol suitable shape and position, to allow the passage at car or other tluid to the con1-- partrnents torming'hetween the vanes, the air entering through large openings or tightened portions 28 on the end cover. The diaphragm or drum carrier 20 this suction end may he provided. with tan vanes 29 which will give an initial pressure to the air supplied and thus increase the capacity ot the machine.

The port plate on the delivery side (not shown in the drawing) has a port dtl or ports of suitable shape and disposition tor the passage oil the air from the compartments as they hecoine smaller in site and finally disappear.

Figs. 5 and h s onal end ele comprises a rotor s drical rotor sliding vanes l2 distances apart.

some distance at each end an hy hall or other suitable hearings l3 carried loy circular dished end plates or covers it so that the hearings 13 come in eccentric positions with respect to the dished covers. These covers have internally projecting arms 15 or a ring termed w the outer race ot a large loall hearing 17 which is concentric with the cover it. Tn the inner race is mounted a sleeve 18 through which the rotor shaft 10 passes eccentrically, where it comes intermediate the rotor and the hearing of the shaft. This sleeve is extended into a disc or ring l9 which comes at a slight angle to the vertica loent to the horizontal where it with a vertical flange. device terms a cylinder or drum carrier 20 and is freely rotatalole in its large ball ith a housing 16 :tor

how a term at the rotary compressor or the lilrc made according to the invention which comprises means tor oppos ing a contrary or haclr pressure to balance possible lealrapge. lln this form the rotor ll with its associated sliding vanes lit is eccentrically mounted with respect to an cncircling treelyrotating drum or cylinder 2t in a manner previously explained. in place however cl providing special port plates 22 in the open ends of the rotary cylinder t e fixed framcworlr carrying the bearings oil the rotor shaft ll is formed with side plates 31 coming against and closing in the open ends of the rotary cylinder 21. One ,or looth of these side plates is or are formed with the inlet 30 to the chamloers. T shaped and as shown in Fig. 6 disposed relul and is then This sleeve and ring A revolving cylinder or drum 21 with end flanges is. arranged around the rotor ll and. vanes 12 and its flanges bolted or otherwise fastened to the flanges of the carriersQO. ortion of the rotor 11 comes into contact w th or closely adjacent the lowermost portion of the internal surface of the cylinder or drum 21 and the vanes 12 art 37 or outlet port use ports are suitahl y ltltl lllll llll llttl tively to the chambers and to each other and may be of somewhat elongated form in a circumferential direction.

These side plates 31 are so formed that portions or extensions 32 thereof combine to form a somewhat annular chamber 33 surrounding the rotary cylinder 21. In- Wardly projecting flanges 34 are provided on the side plates 31 to project over the exterior of the ends of the rotary cylinder 21 and the inner surfaces of these flanges come adjacent screw threaded portions 35 on the exterior of the rotary cylinder 21. The crests of the threads of these screw threaded portions have a very slight clearance from the surfaces of the flanges 34 which come adjacent thereto and the screw thread on one side is right handed whilst the screw thread on the other side is left handed.

The annular chamber 33 surrounding the rotary cylinder is kept supplied with .011 of a desired consistency and the direction of rotation of the apparatus is so chosen that the action of the screw threads on the exterior of the rotary cylinder 21 is such that oil is forced along the said threads under pressure to the outer ends of the cylinder which run in contact or substantially in contact with .the inner surfaces pf the fixed side plates 31. The pressure 011 thus fed in opposes any leakage past the ends of the cylinder. I

With this form of construction and with any other desired and suitable form the rotary cylinder 21 may be carried as shown by an encircling ball, roller orpther bearlng 36 so that it rotates in the said bearlng, or

in place of a single hearing more than one may be provided in suitable positions. For

large cylinders or drums, suitably arranged and positioned roller bearings or the like which do not encircle the cylinder or drum ma be provided for the same purpose.

nFigs. 3 and 4 the compressor comprises a port plate at the pressure end formed from a casting or the like. This casting has a central sleeve portionv 37 through which the rotor shaft 10 passes and at one end adjacent the rotor 11 hasa flat plate portion 38 forming the port plate proper. This port plate 38 is circular and extends to cooperate with the flanged portion of the rotary cylinder or drum 21 the parts in this position having, co-operatmg baflle means as hereafter described. The casing has another wall 39 spaced from and at a slight angle to the port plate 38 which joins the port plate 38 in a curved portion at its greatest diameter and which merges into the sleeve 37 towards the centre. The port or ports in the port plate (not shown in the drawing) open into the hollow 1nterior 40 of the casting thus formed. An outlet or outlets 40 from the hollow inte tions 47 are rior of the casting is provided above the sleeve and at this portion the casting comes within and may be concentric with the sleeve like portion 41 of the carrier 20for the cylinder or drum 21 which sleeve portion 41 of the carrier is mounted to rotate in the inner race ofthe large ball bearing supported by the inwardly extending flange or diaphragm.

The cover for the parts and carrying the bearing for'the rotor shaft 10 is made at this end in two portions which are attachable. An inner portion 42 which is bolted to the outer casing or base framework 43 and which has formed integrally therewith the inwardly extending flange or diaphragm 44 carrying the large ball bearing and an outer portion 45 which has the air outlet therein and which carries the bearing for the rotor shaft 10 and has an inte- In the closed annular space between the ring or diaphragm and the exterior of the.

hollow port plate the carrier 20 for the rotary cyhnder or drum 21 islocated and 'it will be appreciated that the air under pressure delivered through the port plate does not come into contact therewith as this carrier 20 is enclosed and shielded by the outenpart 39 of the port plate, the ring or diaphragm and the ring like channel portion of the outer casting.

The baflling means employed between suchport plate and the adjacent part of the rotary cylinder or drum are preferably as shewn in Fig. 4. In this figure a number of concentric and spaced rin s or projecrovided on the flanges of the rotary cylin er or drum 21 and may be formed integral therewith, projecting into a number of cooperating concentric and spaced channels 48 on the fixed port plates 38, the arrangement being such that the rings 47 do not touch the sides or bases of the channels 48, further the flanges of the rotary cylinder or drum referably do not touch the port plates. 1e rings in some cases may be on the port plates and the channels on the flanges or each part may have both rings and channels.

An exhauster or vacuum pump can be constructed generally similar to the compressor described except that the intake will be enclosed; to enable the same machine to be used both for compression and ex- Fill the rotary cylinder or l other eatrenn y corne on the s on th i hetween the anes lit. To prevent compressor or the lilre oracle accor invention is shown in F l antl prises ring-like side plates to v one or hoth entls of the rotary e the lilre 2?. anti projecting y flanges or the like as shown. These ring-lilre Shh plates eatencl inwartily to a sufiticient eutent to overlap the entls of the rot- 1' a closiretl amount in every relative pos ion of the rotor. 'llhe overlapping portion is provided with an annular or circular recess till in which is locatecl a paclring ring" al or other suitable material lrept pressed into contact with the cool surface of the rotor ll hy suitahle springs or the hire not By this construction it will he seen that t .e side encls or etlges 52 of the vanes lit hich project from the rotor ll wor t in com with the inner surfaces of the rin e plates t9 which rotate with the cylinler or clrurn 21. lit will also he unolerstootl that any possihle lealrage has to pass hy' the spring pressed patching 5f loetween the saicl ring-litre sicle plate and the curl of the rotten The ring-litre sitle plate at one or hoth sioles is made to turn around fires cast ing or the hire 59 formed with means tor carrying the hall or other hearing or hear for the rotor his or also carries one portion of the e the other portions of which are currietl hy eutensior from the ringlilre el -9 "lhe castings at the also p shapetl for ezrarhple as shown pletely enclose the hearings cylinder or the litre,

The enols of the rotor tions which are orerlappetl hy' th projecting ring-lithe entl pl coins into tact with portions the tired ca aronntl which the ring lilite plr' rotate and in suitahle positions this o proritletl with suitnhly shaped. inlet nncl outlet ports.

Alternatively casting con suitahly shapeol inlet lancl outlet to rnacle as a se arate piece from the T casing until. he heltl in contact nth of the rotor hy springsor the li pressure arrangetl to op on the A i the casting containing bllfi inlet eh o i A ports, The rotor portions hetween the runes is also foirneol with pas tluits 55 atlaptecl to coincirle w outlet ports in suitahle positions oonoluits one extremity come in the entl or enels of the rotor she t antl at the from the inlet or outlet ports a, cnsting into or'through the slots or tilt rotor l.

l in which slots or recesses he clo not open. into or communicate with o inlet or outlet ports For this purlower surface of these openings or the encls are correct away re" the C'Bllh e of rotation of the rotor hewn at 58 to such eirtcnt that at their eutreinities th. coine raclially further from the o e rotor than the outermost the inlet or outlet ports 59.

in detail in lhigure 9.

shown This is ln. seine where the rine lihe sitle checl to the rotary cylinder 9J1 e casting carrying the hear ancl the saitl rotary cylinl'l sitle plates or the eel-- jacent set F .e casting may he proriolecl with threacls of opposite hanrl at each siole of the machine so that oil locatecl the which surrounds the hearings of e rotary cylii may he force cl hy "l w 'L. H action through the o pose a cont ary pressure he construction to s. 5 antl 6.

"he invention it rstootl that lie inlet anol out c A i or forrnetl in one entl ioth onus". ll some cases the inlet can one entl a iilst outiet is arrangecl should also he fully on- .n all the inlet ancl onttalre i l ce through the open otary cyl or clruin.

"eat to the precise A ails of constr ction tlescrihetl as s n on he ruriecl to suit particular cases, now norticularly olescrihecl and so llllftit of my saitl inrention her the same is to he per yet what ll claim. i

casing; means P each entl of in saicl projecting at each hollow cylinder, sleeres the inwardly projecting hearings loco/reel hetwecn the for supporting hall iection with the casing so e tier freely to rotate hearings forrnecl with aft niounteol in saitl hear pistes til at a n U o t the r t anrl disposed within the lintlen, the axis of the rotor arallel anol out of is of the cylincler ancl cc of the rotor ly into contact mam with the inner circumferential surface lot the cylinder, a number of radially arranged slots in the rotor extending parallel to the axis thereof, a number of sliding vanes monntedin the said slots, the outer edges or which vanes are adapted to extend to and contact with the inner circumferential surlace cf the freely rotating cylinder, means lei" closing theopen ends of the freely rotatingcylinder so that the crescent shaped space between the outer circumferential surface of the rotor and the inner circumferential surface of the cylinder is divided into a number at chambers by the vanes, port plates connected to the casing arranged at each end of the freely rotating cylinder and the rotor, ports in the port plate for c0n1- municating with the chambers between the blades, inlet means in the casing in connec- W tion with the port in one port plate, and

coincidence with the outlet means in the casing in connection with the pert in the other port plate.

2. A rotary pump as claimed in claim 1, in which the inwardly rejecting flanges of the freely rotating cylinder act as closures for the chambers between the blades and overlap the ends of the rotor in all relative positions, packing means being provided between these overlapping portions and the rotor,

3. A rotary pump as claimed in claim 1, in which passages are provided through the rotor to cause the ports in the port plate to be put into communication with the chambers between the blades atappropriate times, and in which the ends of the radial slots in the rotor are prevented from coming into orts. In witness whereo I afiix my signature.

HARRY SKEET BROOM. 

